Unilateral Warthin Tumor Mimics Cystic Pleomorphic Adenoma

Further noncontrast CT scan was performed, which revealed well-defined, well-circumscribed smooth marginated solid cystic lesion in superficial and deep lobes of left parotid gland, predominantly in posteroinferior part of gland, medially the lesion extends into stylomandibular tunnel (Figure 1). On postcontrast CT, irregular nodular enhancement of solid part was noted and in close relation to left external carotid artery and IJV, and antero-inferiorly retromandibular vein was compressed by the lesion (Figure 2). On noncontrast MRI, T2WI showed heterogenous signal intensity, T1WI images showed isointense signal within lesion and coronal showed slight hyperintense signal (Figure 3). There was no evidence of any enlarged cervical or intraparotid lymph nodes. On basis of unilateral solid cystic lesion in middle-aged patient with irregular nodular enhancement of solid part of lesion with isointense signal on T1 and slight hyperintense signal on STIR images suggestive of two differential diagnoses were: 1. Cystic pleomorphic adenoma (due to unilateral solid cystic parotid lesion in middle-aged patient, enhancing solid part and no adjacent intraparotid and cervical lymph nodes) 2. Warthin tumor (due to irregular nodular enhancing solid part with isointense signal on STIR MRI) Further ultrasound guided FNAC was taken, aspirated material appeared chocolate brown. On smear examination, oncocytes and lymphocytes cells were seen (Figure 4). Patient was operated on and histopathology revealed cystic spaces lined by a bilayer of oncocytic cells and abundant lymphocytes in the sub epithelial stroma (Figure 5).